Tube roll mechanism for paper making machines



' `lune 8, 1937. w, CLNASHy TUBE ROLL MECHANISM Foa PAPER MAKINGMACHINES Filed Nov. 13, 1935 2 Sheets-Sheet l kwh@ June 8, 1937. w. CNASH n TUBE noLL MECHANISM FOR PAPER MAKING MACHINES 2 Sheets-Sheet 2Filed Nov. 1 5, 1955 APatented June s, 1937' PATENT OFFICE TUBEMECHANISM EOR PAPER MAKING MACHINES William C'. Nash, Neenah, Wis.,assigner of oncfth to Mary Jones, Neenah Wis.; one-i'th to William M.Nash, Chicago, lll.; one-lth to Roy A. Nash, New Rochelle, N. Y.: andone- 'ilfth to Marie Duvall Nash, Neenah, Wis.

Application November .'13, 1935, sentano. 49,469 .2 Claims. ((21.l92-44) This invention relates to improvements in paper maidng machinesand refers specically to an improvementin'the tube rolls of a papermaking machine of the Fourdrinier type.

5 In the making of paper on a Fourdrinier type oi' machine, the pulp'predominantly liquid, is discharged from the head box onto a movingwire or screen. 'I'he wire or screen passes over a series of tube rollswhich contact the lower face of the screen and assist in tion of thewire. The tube rolls are usually of relatively small diameter and arerotated by` their contact with the moving screen.

Of course, since the tube rolls are rotated by their contact with'thescreen, the -peripheral speed oi' the surfaces of Vsaid'rolls will besubstantially equal to the speed of travel of the screen and the angularvelocity of said rolls will 20 depend upon thespeed of travel of thescreen and the diameter oi' the rolls. When operating the paper makingmachine at low speeds, the screens, of course, travel at relatively low-speed 'and hencethe rollsare not rotated at an ex- 25 cessive angularvelocity. However, as the speed ofv travel of the screen increases,thereby increasing the angular velocity of the rolls. diiiiculty isencountered due primarily to centrifu.

gal action oi the rolls upon the liquid carrier of 3 the pulp whichseeps through the screen onto the rolls, and also upon the fact that thefront sides oi' the rolls travel upwardly toward the screen and the rearor trailing sides of the rolls travel downwardly and away fromthescreen.

5 'I'hese phenomena, although present at all screen speeds, areaccentuated at high speeds and tend My invention is specificallydirected to the;

elimination of this diiiiculty and resides broadly in the provision ofmeans for decreasing the rate 50 of rotation oi'- the tube rolls,particularly those adjacent the head box. vIn other words, by theinvention. one of the above mentioned factors which cause disturbance ofthe iibers upon the screen is eliminated.

f 55 'In reduce the speed of said tube rolls that the removal of theliquid from the pulp carried upon 'the upper poris, to render the speedof the tube rolls independent of the speed of travelof the. screen, Iprovide an arrangement whereby the axes of the 'tube rolls can be movedat a desired rectilinear speedlin the direction of travel of the screen.5' By correlating the speed of translation of the'` rolls with the speedof translation of the screen theV rolls can be-caused to rotate at-aperipheral speed substantially equal to theI diierence ofY said speedsof translation. .This ldierence inv 10 speed may be either positiveornegative, that is,

if the speed ofv translation of the screen exceeds the translation speedof the rolls, the rolls will rotate at a peripheral speed, equal to thedif- Y ference, in the direction oftravel of the screen, or if thetranslation speed of the rolls exceeds u the speed of the web, therolls. will rotate in the opposite direction to the direction oi' travelof 'the screen. However,g in controlling the rate of rotation of therolls, as described, the ultimate function oi' said rolls, that is, toassist in the removal of the liquid carrier, is in nowise diminished.

Other objects and advantages vof my invention will be apparent from theaccompanying drawings and following detail description.

In the drawings, Fig. 1 is a fragmentary side elevational view, partlyinv section, oi' a portion of a paper making machine, illustratingparticularly an embodiment of my invention as ap- '30 plied to the tuberolls. A

Fig. 1a is a continuation of Fig. 1, illustrating the detlectors betweensome of the tube rolls.

Fig; 2 is a diagrammatic detailed view, illustrating the disruptiveaction oi' a conventional tube roll upon the paper web.

' Fig. 3 is a sectional view taken on line 3-3 of Fig. 1.

Fig. 4 is an enlarged fragmentary. detailed sectional view, illustratingthe use of the defiectors which lcomprise an embodiment of'my invention.

Referring in detail to the drawings, I indicates one of two oppositelydisposedside frames which may be positioned on opposite sides of laportion of the wet end Aof a paper making machine 2.

A hanger 3 carrying an open bearing 4 is mounted upon an end of each o1'the frames I in which opposite ends of shaft 5 are journa-iled, saidshaft v carrying breast roll 6. A Fourdrinier wire or screen Tpassesaround breast roll 6 in the convention'al manner and travels in the.direction indicated by the arrow. v

A sprocket vwheel 8 may be mounted upon each Side of the machine 2adjacent the breast roll 6 55 -70 quantity of pulp Il.

g over which'each of the chains passes. Sprocket 'chains 0 at the upperportion of their travel move A in vdirection as screen 1,' either wheelslor Il constituting the 4driving wheels. Howevtl'. the drivingof thesprocket wheels is independent ofthe driving of screen I-and; as willthere will be relative motion `between the two.

Each of the chains l carries spaced brackets Ii chains. the bracketsupon opposite chains'being in transverse alignment.l A tube roll i2 maybe carried between each pair of aligned brackets ii, said rolls eachhaving oppositely projecting stub -shafts I3 which may be Journalled inthe respective brackets Ii. v e

A track structure il is mounted upon each the framesi below the pathoftravelof screen 1, said structure being secured -to said frames by.means of bolts Il or the like. 'lhe track structure il is oval shapedand traverses the path of travel of the chain 0. The inner face of eachoval track structure is provided with a recess Il which also defines an`endless oval pathsimilar 'niscarrieaoneacn'stubshaft n enamora diameterslightly lessthan the width of the reby rolls i! and the weight ofjsaidand @insteadofbeingcarriedby carried by the track, structure I0.`hereinbefore described. chains sareadaptedtobedriveninthesamedirectionas Y in view of the Afact thatscreen 1 contacts the surfaces of said rolls and thereby 50 rotates saidrolls. the peripheral speed ofthe rolls will be substantially equal tothe difference (either mi! pressure of the pulp causes averita'blecataract Mxucmd through thescreen adiacent the headA In rig. 2 adiagrammatic view-of a conventraveling at a rapid rate, the head of pulpIl in headbox Il mustberelativelygreatin order that the proper amount ofpulp be deposited upon the wire. Another result of the rapidly movingscreen 75 i'l' is that roll il and the remaining tuberolls 111,088,841vl (not shown) are revolved at a terrific rate. As I be hereinaftermorefully described. the speed.i of the chains I and screen 1 isfdifferentso that which may be mounted upon of the to the loci of the chainU Aball-bearing. roller at thefupper portion of travel ofsald' the head boxwhich Adisclial'gd the screen decreases below a criticalmoving'screen-with sumcient pulp. This thosetuberollswlthinsixorelghtfeetfrom breastrolluponthemovingchaim has been hereinbefore described.-the of the pulp 20 in the head box drives the liquid carrier andportions of the pulp through the screen in a cataract, as indicatedbythe arrows at Il.'

In -addition. for a considerable period of travel l' of the screen thepulp upon the screen dehydrates at a rapid rate, the liquid carriershowering through the screen. A portion of this liquid is. carried uponthe surfaceofthe rapidly rotating tube rolls and by centrifugal'force isthrown from the roll at a rapid rate in the direction of the resultantof the radially acting centrifugal force and the tangential force, whichlatter is a result of centrifugal force and the phenomena of surfacetension which causes the liquid to adhere -suillciently to the surfaceofthe roll to have tangential motion imparted to it when it is thrownfrom the roll. This action of the tube rolls builds up a pressure soneat 22; that is, adJacent the advancing side ofthe roll Il, and a reducedpressure sone 2l adjacent the receding side of the roll'. The pressurein the zone 22 tends to lift the fibres from the screen surface andotherwise Adisturbs the original desired lay of the libres. The 'reducedpressure zone 23 tends to suck the nbres. d own upon the screen surfacewhich tends to impartan objectionable wire mark upon the paper. v Inaddition. pin-holes'are formed and a one-sided shade is imparted tocolored paper. Consequently. the tube rolls of the conventional papermakingmachine constitute one of the most serious limitations to thespeed of the machine.

It can readily be seen therefore, that by con- A trolling the rateofrotation ofthe rolls i2 independent ci thespeed of the screen 1. thedimculitherollslfwillbesorotatedastohaveaperipheralspeedofwfeetperminuteinaclockwise or positive direction and in thelatter case the rollswillhaveaperipheralspeedofwfeetper minute in acoimterclockwise or negative direcabove tion.

rnview ofthe-racetmtnemmmmymmm`iacenttherolls,thedisruptiveeffectoftherapidlyrotatingrollswillnotbe'aspronounced the rate-of dehydration of 'theinstance, it may be found suiiicient to mount However, invention broadlycontemplates motmtingall numberlessthanalluponamovingcarrien@Asthescreenprogressesoverthe tablecrr rolls. the web upon thescreenloseswater diminishingrate andeventhoughthetube .arerota'tedatarapidrate,the`mass ofliquid volvedvdoes not a disturbance of the stion. '0f course,any'desired diuerence ofscreenvorchainspeedmaybeadoptedandthe exampleisnottobeconstnxedasalimita Icontemplate mounting, in any convenient manner, bams plates ordeiiectors 24 between th'e vrolls si which latter may comprise the usualtube rolls with laterally immovable axes. The bailies or de` ectors maybe T-shaped in section with the stall oi the T vertical and betweenadjacent rolls and the cross-portion of the T horizontal and adjacentthe lower race of the screen. With this arrangement the pressure andvacuum zones -will be broken up and the liquid thrown by centrifugalforce will not be permitted to injure the web.

The baes N, oi course, could be used between adjacent tube roll oi' theconventional paper making machine and in themselves would reduce theinjurious eect o! the rotation of the rolls.

Reverting to the chain mounted rolls, it will be noticed that, inasmuchas the rolls rotate freely, there will be no undue friction between thescreen undersurface and the rolls, as would be the case were the rollsstationary. This, of course, preserves the life of the delicate,relatively expensive screen.

It is to be understood that, the carrier for the rolls i2 need notnecessarily be a sprocket chain, since my invention broadly contemplateslateral movement of the axes of the rolls l2 by any means stance, toprevent the excessive passage of illler through the screen, the chainsmay be driven at l a linear speedin excessror the speed of the screenwhereby the rolls l2 will be rotated in a counterclockwise direction.Broadly, myinvention contemplates both methods of operation.

I claim as my invention:

v1. In combination, a paper making machine comprising a frame, anendlessly moving paper forming'screen carried by said frame, a pluralityof rotatable tube rolls over which said screen moves and upon which saidscreen is supported,

a conveyor ior moving said tube rolls laterally in a plane parallel tothe plane of motion of said screen, said frame being provided with achannel opening towards, and on each side of said conveyor, saidchannels paralleling the path of travel of said screen, a bearingcarried at each end oi each of said tube .rolls adapted to travel insaid channels whereby movement of said tube rolls at right-angles tosaid channel is limited.

2. In combination, a paper making machine comprising a frame, anendlessly moving paper forming screen carried by said frame, a pluralityof rotatable tube rolls over which said screen moves and upon which saidscreen is supported,

an endlessly moving conveyor for moving saidA tube rolls laterally in aplane parallel tothe plane of motion of said screen, said conveyor oversaid sprocket wheels, a bearing carried at y each end of each of saidtube rolls adapted to .travel in said channels whereby movement of saidtube rolls at right-angles to said channels is limited,

WILLIAM C. NASH.

